Miller Dynasty 200DX
According to the manual, the max amperage used by the machine will be 30 amps and it recommends to use 10 gauge wire for the run. Oddly, the machine comes wired with 12/4 wiring rather than the 10/4 that you would expect. I will change this wire to 10/4 when I get a chance to pull the machine apart:
The adapter/extention cord was wired with a Pass & Seymour Turnlok Locking Connector, L1430C, 30A 125/250V and a 50 amp, 250V dryer connector with some Carol 10/3 wire.
I will make a similar cord for use with 30 amp, 115V.